Horizontal acceleration of the wedge (assuming the block and wedge move together horizontally):
A=M+mf=10+224=2 m/s2
Working in the non-inertial frame of the wedge, the block experiences a pseudo force mA directed opposite to the wedge's acceleration. The components along the incline are:
Component of gravity down the incline: gsin37∘
Component of pseudo force up the incline: Acos37∘
Net relative acceleration of the block down the incline:
arel=gsin37∘−Acos37∘
Using sin37∘=0.6 and cos37∘=0.8:
arel=10(0.6)−2(0.8)=6−1.6=4.4 m/s2
Time taken to slide a distance of 8.8 m along the incline, starting from rest:
s=21arelt2
8.8=21(4.4)t2
8.8=2.2t2
t2=4⇒t=2 s
Hence, the required time is 2 s.
